HONG KONG (Reuters) - A unit of Sinopec Group and brokerage China Galaxy Securities are launching Hong Kong IPOs on Monday seeking to raise up to $3.5 billion in total, injecting life into Asia's moribund IPO markets where deal values more than halved in the first quarter of the year.

The massive initial public offerings (IPOs) have been eagerly anticipated in Hong Kong and their success could trigger a wave of other deals, ranging from hotel operators to banks looking to sell new shares in coming months.

Sinopec Engineering (Group), a unit of Asia's largest oil refiner Sinopec , is offering 1.33 billion shares in an indicative range of HK$9.8 to HK$13.1 each, putting the deal value at up to HK$17.4 billion ($2.24 billion), sources said on Sunday.

At the top end, the deal would be Hong Kong's largest IPO since People's Insurance Company (Group) of China raised $3.56 billion in late November.

The offer values Sinopec Engineering at 9-12 times its forecast earnings in 2013, added the sources, who declined to be identified because details of the deal are not yet public.

China Galaxy Securities, whose larger rivals include Citic Securities and Haitong Securities , is offering about 1.5 billion shares in an indicative range of HK$4.99 to HK$6.77 each, the sources said. The range is equivalent to a price-to-book ratio of 1.19 to 1.49 times.

The company initially planned for a dual listing in Shanghai and Hong Kong, but gave up plans for a simultaneous offering in mainland China after the country's securities regulator froze IPO approvals late last year.

The two deals underscore a pick-up in activity after IPO issuance in Asia ex-Japan plunged 56 percent to $3.3 billion in the first quarter, making it the worst start to a year for new share listings since the first quarter of 2009, according to Thomson Reuters data.

IPOs in Hong Kong are down 20 percent so far in 2013 from the same period of 2012 to $1.05 billion, data shows. After holding the crown of global IPO hub for several years, the city had $7.72 billion worth of deals in 2012, the lowest volume since the 2008 global financial meltdown.

Hong Kong's lackluster performance is in sharp contrast to Southeast Asia, where a string of deals including BTS Infrastructure Fund and Temasek Holdings-backed Mapletree China REIT have kept bankers busy.

The two deals rank as Asia's biggest IPOs this year.

Other large deals likely to hit Hong Kong later this year include a series of commercial real estate spin-offs from Hong Kong property and investment companies, including an up to $1 billion IPO by NW Hotel Investments, which is part of New World Development .

Great Eagle Holdings Ltd also plans to spin off its Langham hotel chain through an $800 million IPO, while property and infrastructure group Hopewell Holdings is looking to raise as much as $800 million from a spin-off of its property and hospitality business, Hopewell HK Properties.

Sinopec Engineering was formed last September, consolidating eight engineering and construction units of Sinopec Group, as the state-owned giant looks to expand its business overseas. It is controlled by Sinopec Group and Sinopec Corp , which hold stakes of 2 percent and 98 percent, respectively.

Citic Securities , JPMorgan and UBS were hired as sponsors of the Sinopec Engineering offering.

China Galaxy International, Goldman Sachs and JPMorgan are acting as sponsors of the China Galaxy deal, with a group of 13 other banks also helping to arrange it. The number of banks on the IPO puts it near the record 17 hired by PICC for its listing last year.

(Reporting by Elzio Barreto and Fiona Lau of IFR; Editing by Denny Thomas and Nick Macfie)